Efficient way to access off-screen buffer memory

Hi,
I have a graphic application the draw images into off-screen buffer. 1000 times in a second the buffer pixels should be captured to memory. ( I need to pass the off-screen pixels to another application that compress the frame.) I have a code sample that uses CreateDIBSection and pass pBits. This way pBits provides me direct access to the pixels.

What is the most efficient way to do it?

hDesktopCompatibleDC=CreateCompatibleDC(hDesktopDC);
hDesktopCompatibleBitmap=CreateDIBSection(hDesktopDC,&bmpInfo,DIB_RGB_COLORS,&pBits,NULL,0);
if(hDesktopCompatibleDC==NULL || hDesktopCompatibleBitmap == NULL)